Relays are switches that open and close circuits electromechanically or electronically . Relays control one electrical circuit by opening and closing contacts in another circuit. As relay diagrams show, when a relay contact is normally open (NO), there is an open contact when the relay is not energized. Specifications: Contact Load: Low Power Usage: General Purpose Theory: Voltage Relay Model Number: JZX-22F(D)-4Z Protect Feature: Sealed Package Includes: 1 x CHINT JZX-22F/4Z AC220V(R) General Relay